Background: Psoriasis is a chronic autoimmune skin disorder characterized by the rapid growth of skin cells, leading to the formation of thick, scaly patches. The present study was conducted to assess the clinical efficacy of Monochromatic Excimer Light (MEL) in the treatment of psoriasis. Materials & Methods: 74 cases of psoriasis of both genderswere treated by MEL, two sittings per week. PSI was calculated before and after treatment which was derived from the standard Psoriasis Area and Severity Index (PASI) by omitting the area, thus assigning a score of 0-4 (0=none; 1=mild; 2=significant; 3=moderate; 4=severe) for erythema, induration and desquamation. Results: Out of 74 patients, 30 were males and 44 were female. Common site was scalp seen in 35, trunk in 38, palms in 12, upper limb in 67 and lower limb in 71 cases. Outcome was excellent in 62, good in 10 and moderate in 2 cases. The difference was significant (P< 0.05). before treatment PASI score was 7.4 and after treatment was 1.3. The difference was significant (P< 0.05). Conclusion: MEL is a safe and efficient treatment for plaque psoriasis, and the results are primarily dependent on the patient's skin phototype and the anatomic location of the lesion.